Apparatus for testing rail-roads.



G. R. STURDEVANT.

APPARATUS FOR TESTING BA-IL BONDS.

APPLICATION FILED MAR. 31, 1909.

Patented Sept. '7, 1909.

2 SHEETS SHEE1' 1.

WITNESSES 0. R. STURDEVANT.

APPARATU$ FOR TESTING RAIL BONDS.

APPLIOATION FILED MAR. 31. 1909.

Patented Sept. 7, 1909.

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-UTNITED STATES PATENT OFFICE.

CHARLES R. STURDEVANT, OF WORCESTER, MASSACHUSETTS, ASSIGNOR T AMERICANSTEEL & WIRE COMPANY, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF NEWJERSEY.

Specification of Letters Patent.

Patented Sept. '7, 1909.

Application filed March 31, 1909. Serial No. 486,950.

1 T 0 all whom it may concern:

Be it known that I, CHARLES R. sTURDE- VANT, of Worcester, in the countyof Worcester and State of Massachusetts, have invented a new and usefulImprovementun Apparatus for Testing Rail-Bonds, of which the followingis a full, clear, and exact description, reference being had to theaccompanying drawings, forming part of this specification, in which-Figure 1 is a side view, showing a portion of the apparatus applied to atrack rail; Fig. 2 is a plan view of the same; Fig. 3 is a section onthe irregular line IIIIII of Fig. 2; Fig. 4 is a diagrammatic Viewillustrating the use of the apparatus; and Fig. 5 is a detail View of aportion of the apparatus.

My invention has relation to apparatus for testingrail bonds, and isdesigned to provide means of simple and eflicient character, whereby theconductivity or resistance of a railbond may be quickly and easilyascertained.

The nature of my invention will be best understood by reference to theaccompanying drawings in which I have shown the preferred embodimentthereof, and which will now be described, it being premised, however,that various changes may be made in the details of construction andarrangement of the parts without departing from the spirit and scope ofmy invention,.as defined in the appended claims.

In the drawings, the numeral2 designates a piece or bar of insulatingmaterial hav-- ing at each end a metallic strap 3, suitably securedthereto. Each of these straps 3 has a depending lug 4, which carries acontact point 5. Attached to the central portion of the bar by means ofthe side plates 6 and bolts 7 is a socket plate 8, in which is pivoted alever 9, having a short arm or heel 10, extending'below its pivot. Thesocket plate 8 is adjustable on the bolts 7 to adapt the device to railheads of different widths, a plurality of washers or spacers 10 beingprovided for the purpose of enabling the proper adjustment to beconveniently made.

11 designates a bar, preferably of wood, to the lower end of which issecured a metallic socket piece 12, having a contact point 13. securedin its lower end and also provided with a binding post or screw 14, forthe attachment of a flexible conductor 15.

Secured to the socket piece 12 is a self-winding tape measure 16. j

17 designates an electric measuring or indicating instrument, which ispreferably a diflerentially wound milli-volt meter of a well known type,having its zero point in the center of its scale. This volt meterisprovided with three binding posts or screws 18, 19 and 20, the conductor15 being connected to the binding post 18, and two flexible conductors21 and 22 leading from the binding posts 19 and 20, respectively tobinding posts 23 and 24, carried by the straps 3, at the ends of the bar2.

25 of Fig. 4 designates a rail bond tobe tested.

The apparatus is used as follows: The bar 2 is preferably provided witha plurality of holes 26, to provide for the adjustment thereon of themetal end straps 3, so that the two straps can be set at the desireddistances apart corresponding to the length of the rail bond to betested. The straps are adjusted so that the two contact oints 5 willspan the bond 25 to be tested, in the manner shown in Fig. 4. The bar 2is applied to the rails in the manner shown in Figs. 1, 2 and 3, and thelever 9 is pulled to one side, thereby forcing the contact points 5through any rust or scale which ma be resent on the surface of the railan making a positive and reliable electric contact therewith. If acurrent. be flowing through the rail, the needle 27 of the instrument 17will be deflected in onedirection, the amount of its deflectiondepending upon the strength of the current and the conductivity orresistance of the joint. At a short distance from the contact 5, towhich the conductor 21 is connected, the contact 13 is applied to therail in the manner shown in Fig. 4. A current will then flow through theinstrument from this contact and will cause a deflection of the needle27 in the opposite direction; and the cont-act 13 is moved along therail until a point is reached where there is no deflection of the needle27 in either direction. At this point the fall of potential in the uncutrail between the contact l3 and the nearest contact 5 will equal thedrop of potential in the joint between the two contacts 5, and theresistance of this portion of the rail will be equal to the resistanceof the joint. One end of the selfwinding tape is connected to theadjacent end of the bar 2 (which is provided with a hook 28, for thispurpose) and the length of this portion of the rail can then be readdirectly on this tape 'in feet and inches. This is the desired readingand gives the resistance of the joint, as measured by the resistance ofthe length of the uncut portion of the rail, so found. The instrument 17is used simply as an index to indicate when the two potentialdifferences are equal and when one cancels the effect of the other, theneedle is at zero and no readings'of the instrument are necessary, theonly reading being from the tape.

The instrument can be made very sensitive and can be readily operated byone man.

The instrument can be provided with the usual multiplier, by means ofwhich the movement of the indicator or pointer can be decreased if itsdeflections are too large.

If the current flows continuously through the rail, the operator canwork very rapidly from joint to joint to be tested, and it is notnecessary that the current through the rail be uniform. I i

The instrument 17 may be provided with a suitable strap 29, so that itcan be passed around the neck of the operator, and thus leave his handsfree for the manipulation of the contacts.

The bar 2 is preferably provided with one of the hooks 28, at each end,so that it can be a plied to the rail either end'to.

It will be obvious that various changes may be made in the details ofconstruction and arrangement. Thus, the bar 2 may be of various forms,the contactscan be carried thereby in diflerent ways, and other detailscan be changed.

I claim:

' 1. Apparatus for the urpose described. comprising a' differentiallywound indicating or measuring instrument, having its windings arrangedto produce opposite effects upon an indicating device, a contact otherand arranged to span the bond to be' tested, flexible conductors forconnecting the contacts with the measuring instrument, an

other contact device movable toward and. away from the-first namedcontact device and also having a connection with the windings of theinstrument, and means for measuring the distance between the last namedcontact device and one of the first named contact devices, substantiallyas described- 2. Apparatus for the purpose described, comprising aportable measuring or indicating instrument, contact devices for makingcontact with a track rail at op osite sides of a rail bond and also at avaria le distance from the bond .at one side thereof, flexibleconductors connecting the contact with the, windings of the instrument,and means for measurlng or indicating the distance between the lastnamed contact andone of the first named contacts, substantially asdescribed.

3. In apparatus of the character described, a bar having a contact pointadapted to engage a track rail, another bar or support also having acontact point, and a measuring tape carried by one of said bars andarranged to be used to indicate the distance between the two contacts;substantially as described. a

4. In apparatus of the character described,

a bar or support, a pair of contacts adjustably mounted on said bar orsupport and insulated from each other, another bar or sup port having acontact point, a measuring tape carried by the last namedbar'or's'upport, and means on the first named bar or su port forengagement with the free end 0 the measuring tape, substantially asdescribed.

In testimony whereof, I have hereunto set my hand. y

CHARLES R; STURDEVANT. Witnesses: p i

WM. A. BACON,

vGr. SAMPSON.

